org.cast.isi.page.ISIStatelessPage.java Source code

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Here is the source code for org.cast.isi.page.ISIStatelessPage.java

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/*
 * Copyright 2011-2015 CAST, Inc.
 *
 * This file is part of the UDL Curriculum Toolkit:
 * see <http://udl-toolkit.cast.org>.
 *
 * The UDL Curriculum Toolkit is free software: you can redistribute and/or
 * modify it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * The UDL Curriculum Toolkit is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this software.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.cast.isi.page;

import lombok.extern.slf4j.Slf4j;
import org.apache.wicket.Component;
import org.apache.wicket.Page;
import org.apache.wicket.request.mapper.parameter.PageParameters;
import org.apache.wicket.util.visit.IVisit;
import org.apache.wicket.util.visit.IVisitor;

import java.util.ArrayList;
import java.util.List;

/**
 * Base page for ISI pages that should be stateless.
 * The login page, for example, should not be tied to a session that can expire and cause logins to fail.
 * 
 * @author bgoldowsky
 *
 */
@Slf4j
public class ISIStatelessPage extends ISIPage {

    private static final long serialVersionUID = 1L;

    public ISIStatelessPage(PageParameters param) {
        super(param);
        setStatelessHint(true);
    }

    @Override
    protected void onBeforeRender() {
        super.onBeforeRender();
        this.checkIfPageStateless(this);
    }

    private void checkIfPageStateless(Page p) {
        if (!p.isPageStateless()) {
            // find out why
            final List<Component> statefulComponents = new ArrayList<Component>();
            p.visitChildren(Component.class, new IVisitor<Component, Void>() {
                public void component(Component component, IVisit<Void> visit) {
                    if (!component.isStateless()) {
                        statefulComponents.add(component);
                    }
                }
            });

            String message = "Whoops! this page is no longer stateless";
            if (statefulComponents.size() > 0) {
                message += " - the reason is that it contains the following stateful components: ";
                for (Component c : statefulComponents) {
                    message += "\n" + c.getMarkupId() + "[" + c.getClass().getCanonicalName() + "]";
                }
            }
            log.warn(message);
        }

    }

}